<template>
    <div id="home">
        <nav-bar class="nav-bar">
            <div slot="center">购物街</div>
        </nav-bar>
        <tab-control v-show="isTabFixed" class="fixed" @itemClick="tabClick" :titles="['流行', '新款', '精选']"></tab-control>
        <scroll class="content" ref="scroll" @scroll="contentScroll" @pullingUp="loadMore" :data="showGoodsList"
            :pull-up-load="true" :probe-type="3">
            <div>
                <home-swiper :banners="banners" ref="hSwiper"></home-swiper>
                <feature-view :features="recommends"></feature-view>
                <recommend-view></recommend-view>
                <tab-control @itemClick="tabClick" :titles="['流行', '新款', '精选']" ref="tabControl"></tab-control>
                <goods-list :goods-list="showGoodsList"></goods-list>
            </div>
        </scroll>
        <back-top @backTop="backTop" class="back-top" v-show="showBackTop">
            <img src="~assets/img/common/top.png" alt="">
        </back-top>
    </div>
</template>

<script>
import NavBar from 'common/navbar/NavBar'
import Scroll from 'common/scroll/Scroll'
import TabControl from 'content/tabControl/TabControl'
import BackTop from 'content/backTop/BackTop'
import HomeSwiper from './childComps/HomeSwiper'
import FeatureView from './childComps/FeatureView'
import RecommendView from './childComps/RecommendView'
import GoodsList from './childComps/GoodsList'
import { getHomeMultidata, getHomeData, RECOMMEND, BANNER } from "network/home";
import { NEW, POP, SELL, BACKTOP_DISTANCE } from "@/common/const";

export default {
    name: "Home",
    components: {
        NavBar,
        Scroll,
        TabControl,
        BackTop,
        HomeSwiper,
        FeatureView,
        RecommendView,
        GoodsList,
    },
    data () {
        return {
            banners: [],
            recommends: [],
            goodsList: {
                'pop': { page: 1, list: [] },
                'new': { page: 1, list: [] },
                'sell': { page: 1, list: [] }
            },
            currentType: POP,
            isTabFixed: false,
            tabOffsetTop: 0,
            showBackTop: false,
            saveY: 0
        }
    },
    computed: {
        showGoodsList () {
            return this.goodsList[this.currentType].list
        }
    },
    created () {
        console.log('创建Home');
        // 1.请求多个数据
        this.getMultiData()

        // 2.请求商品数据
        this.getHomeProducts(POP)
        this.getHomeProducts(NEW)
        this.getHomeProducts(SELL)
    },
    activated: function () {
        this.$refs.hSwiper.startTimer()
        this.$refs.scroll.scrollTo(0, this.saveY, 0)
        this.$refs.scroll.refresh()
        console.log(this.saveY);
    },
    deactivated: function () {
        this.$refs.hSwiper.stopTimer()
        this.saveY = this.$refs.scroll.getScrollY()
        console.log(this.saveY);
    },
    updated () {
        this.tabOffsetTop = this.$refs.tabControl.$el.offsetTop
        console.log('1', this.tabOffsetTop);
    },
    methods: {
        tabClick (index) {
            switch (index) {
                case 0:
                    this.currentType = POP
                    break
                case 1:
                    this.currentType = NEW
                    break
                case 2:
                    this.currentType = SELL
                    break
            }
        },
        contentScroll (position) {
            // 1.决定tabFixed是否显示
            this.isTabFixed = position.y < -this.tabOffsetTop

            // 2.决定backTop是否显示
            this.showBackTop = position.y < -BACKTOP_DISTANCE
        },
        loadMore () {
            this.getHomeProducts(this.currentType)
        },
        backTop () {
            this.$refs.scroll.scrollTo(0, 0, 300)
        },
        /**
         * 网络请求相关方法
         */
        getMultiData () {
            getHomeMultidata().then(res => {
                this.banners = res.data[BANNER].list
                this.recommends = res.data[RECOMMEND].list
                // 下次更新DOM时,获取新的tabOffsetTop值(不保险,可以在updated钩子中获取)
                this.$nextTick(() => {
                    this.tabOffsetTop = this.$refs.tabControl.$el.offsetTop
                })
            })
        },
        getHomeProducts (type) {
            getHomeData(type, this.goodsList[type].page).then(res => {
                const goodsList = res.data.list;
                this.goodsList[type].list.push(...goodsList)
                this.goodsList[type].page += 1

                this.$refs.scroll.finishPullUp()
            })
        }
    }
}
</script>

<style scoped>
#home {
    /*position: relative;*/
    height: 100vh;
}

.nav-bar {
    background-color: var(--color-tint);
    font-weight: 700;
    color: #fff;
}

.content {
    position: absolute;
    top: 44px;
    bottom: 49px;
    left: 0;
    right: 0;
}

.fixed {
    position: fixed;
    top: 44px;
    left: 0;
    right: 0;
}

.back-top {
    position: fixed;
    right: 10px;
    bottom: 60px;
}
</style>
